A seismic isolation apparatus is known which is comprised of a laminated body having alternately laminated elastic layers and rigid layers and a hollow portion defined by inner peripheral surfaces of these elastic layers and rigid layers, as well as a lead plug (lead column) disposed in the hollow portion of this laminated body.
Such a seismic isolation apparatus, while supporting the vertical load of a structure through the laminated body and the lead plug, is adapted to attenuate through the plastic deformation (shear deformation) of the lead plug the vibration in the horizontal direction of the structure with respect to one end in a laminated direction of the laminated body attributable to an earthquake, and also to suppress through the elastic deformation (shear deformation) of the laminated body the transmission, to the structure, of the vibration in the horizontal direction of the one end in the laminated direction of the laminated body ascribable to the earthquake.